复杂岩性储层压裂技术研究

Fracturing of Lithology Complex Reservoir

海拉尔油田断块多、储集类型多、储层低渗透,物性条件复杂、敏感性强,常规压裂效果差,同时受井网与压裂施工成本的限制,无法采用大规模压裂。为此,需扩大裂缝与油藏的接触面积,提高单井产量,才能提高压裂效果。基于对储层岩性复杂程度的准确认识,使用全缝长裂缝形态模拟来优化压裂设计,通过应用可降解纤维+高浓度陶粒缝内暂堵的工艺方法形成了多分支裂缝压裂技术。现场试验14井次,压裂后平均单井日增油3.8 t/d,同时采用多分支缝压裂技术的重复压裂井压裂后产量达到7.0 t/d,超过初次常规压裂产量4.5 t/d,效果明显。

In the Hailaer basin where there are many fault-blocks and diversified low-permeability reservoirs with complex and sensitive physical properties,conventional fracturing is efficient. Moreover,due to limited well pattern and fracturing cost,a large-scale fracturing is impossible. For achieving satisfactory effects,it is necessary to expand the contact area between fractures and reservoirs so as to improve single well production. Based on accurate understanding of the complexity of reservoir,the fracturing design is optimized through simulating the full-length fracture shape,and the biodegradable fiber + high density ceramsite is used for temporary blocking. Finally,a multi-branch fracturing technique is presented. Its 14 field trials show good results-after fracturing,average single-well oil recovery is enhanced by 3. 8 t / d,while the production of the re-fractured well reaches 7. 0 t / d,4. 5 t / d more than the output after initial conventional fracturing.